Part 8-1 Cardiovascular Pharmacology Flashcards
Cardiovascular meds
Largest area of pharmacology
Meds often “wear several hats” and have multiple implications
Diuretics
Act on kidneys: increase sodium and water excretion
Decrease fluid in vascular system
Diuretics Indications
Hypertension
Congestive Heart Failure
Diuretics Examples
Thiazides
Loop Diuretics
Potassium sparing agents
Diuretics Adverse effects
Fluid depletion; electrolyte imbalance Watch for: -orthostatic hypotension -weakness, fatigue -confusion, mood changes
Beta Blockers
- Bind to heart to block effects of epinephrine and NE
- Decreased HR & contraction force
- Can also produce general decrease in sympathetic response
Beta blockers indications
Hypertension Angine Arrhythmias Heart Failure Recovery from MI Migraines Raynauds Situational Anxiety
Common beta blockers
“olol” suffix
Cardioselective and Nonselective
Cardioselective beta blockers
Atenolol
Metoprolol
Others
Nonselective beta blockers
Pindolol
Propranolol
Others
Beta Blockers adverse effects
Bronchoconstriction
Decreased maximal exercise capacity
Orthostatic hypotension
Psychotropic effects
Sympatholytic effect
A general decrease in sympathetic responses
Other sympatholytic antihypertensives
- Alpha blockers
- Presynaptic adrenergic inhibitors
- Centrally acting agents
- Ganglionic blockers
Vasodilators
Act directly on vascular smooth muscle…inhibit contraction
Vasodilators indications
Hypertension
Heart failure
Vasodilators adverse effects
Reflex tachycardia Orthostatic hypotension Dizziness, headaches Edema, fluid retention Avoid systemic heat
Renin-angiotensin system
Neuroendocrine response that helps control BP and other physiological reactions in various tissues
People with excessive RAS responses have….
Increased blood pressure
Damage to CV system
Damage to kidneys
Options to prevent harmful effects of Angiotensin II
- ACE inhibitors
- Angiotensin II receptor blockers
- Direct renin inhibitors
Angiotension converting enzyme inhibitors (ACE)
Inhibit angiotensin converting enzyme
Decrease formation of angiotensin II
ACE inhibitors effects
Decrease BP and long term heart and BV effects
ACE inhibitor indications
Hypertension
Heart failure
Ang-II receptor blockers
- Block Ang-II receptors
- Prevent detrimental effects of Ang II
- May be as effective as ACE inhibitors but fewer side effects
Direct renin inhibitors
Aliskiren: inhibits renin’s ability to convert Angiotensinogen to Ang I
RAS drugs adverse effects
Well tolerated, some nausea and dizziness
Possible allergic reactions
ACE inhibitors cause dry cough
Calcium channel blockers
- Limit calcium entry into vascular smooth muscle and cardiac muscle
- Promote vasodilation, stabilize HR
Calcium channel blockers indications
Hypertension
Angina pectoris
Arrythmias
Calcium channel blocker examples
“ipine” drugs
CCBs adverse effects
Swelling in feet, ankles Orthostatic hypotension Altered heart rate Avoid systemic heat Increased risk of heart attack
Organic Nitrates
Nitroglycerin, isosorbide dinatrate
Organic nitrate route of administration
Sublingual traditionally
Creams or patches transdermal
Organic nitrates primary indication
Angina pectoris
Nitrates primary effects
Dilate peripheral vasculature
Decrease cardiac workload and O2 demand
Venous dilation causes…
Decreased cardiac preload
Blood returning to heart
Arterial dilation causes…
Decreased cardiac afterload
Pressure heart pumps against
Nitroglycerin onset and duration
Sublingual:
1-3 min onset
30-60 min duration
Patches:
40-60 min
8-24 hr
Isosorbide dinitrate onset and duration
Oral:
20-40 min onset
4-6 hr duration
Sublingual:
2-5 min onset
1-2 hr duration
Isosorbide mononitrate onset and duration
Oral:
30-60 min onset
6-8 hour duration
Amyl nitrate onset and duration
Inhaled:
30 sec onset
5-10 min duration
Nitrate tolerance
Continuous adminstration reduces drug effects
Effectiveness restored quickly when nitrates are discontinued
Prevention of nitrate tolerance
Daily nitrate-free intervals
Patch 12 hr on/12 hr off
Nitrates adverse effects
Headaches/Dizziness Orthostatic hypotension Increased vasodilation Sublingual doses: -check drug viability -have drug ready before rehab
Digitalis
Group of agents derived from foxglove plant
-Digitalis glycosides
Used for congestive hart failure
Digitalis mechanical effects
-Inhibits Na-K pump in cardiac cells; accumulates Na in cell
-Increases intracellular Ca2+
-Increased actin-myosin binding
(Stronger cardiac contraction)
Digitalis Autonomic effects
Decreased HR by:
- stimulating vagus
- inhibiting sympathetics to heart
Digitalis Toxicity
- Relatively common 20-25% hospitalized patients on digitalis
- Can be fatal
Digitalis toxicity common symptoms
GI distress Fatigue Confusion Depression Blurred Vision Arrhythmias
Positive inotropes
Acute or severe heart failure
- phosphodiesterase inhibitors
- Dopamine, Dobutamine
Phosphodiesterase inhibitors
Increase myocardial Ca by preventing Camp breakdown
Dopamine/Doputamine
Stimulate beta-1 receptors
Positive inotropes limitations
- Parenteral administration
- Not more effective than digitalis
- Typically used in acute or severe heart failure
